AAPT2: XML configuration file parser.

The XML file is parsed with the aapt::xml::XmlDom parser and actions are
used for the elements we are interested in. This means that there are
cases where a user could add aditional tags/elements to the document
that are technically invalid (acording to the schema) but are ignored by
the parser. This allows us to be more lenient which probably isn't a bad
thing.

Documents have the namespace stripped before processing as the
XmlActionExecutor ignores any elements with a namespace. The namespace
is validated before being removed.

The test cases are all based off the previous example XML file.

Test: Unit tests

Change-Id: I86d7e0dc6347ace3eaa60c1842d59f3cd0d4f749

1 files changed, 432 insertions, 0 deletions

diff --git a/tools/aapt2/configuration/ConfigurationParser.cpp b/tools/aapt2/configuration/ConfigurationParser.cpp
new file mode 100644
index 000000000000..89618d3a4676
--- /dev/null
+++ b/tools/aapt2/configuration/ConfigurationParser.cpp
@@ -0,0 +1,432 @@
+/*
+ * Copyright (C) 2017 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "configuration/ConfigurationParser.h"
+
+#include <algorithm>
+#include <functional>
+#include <memory>
+#include <utility>
+
+#include <android-base/logging.h>
+
+#include "ConfigDescription.h"
+#include "Diagnostics.h"
+#include "util/Util.h"
+#include "xml/XmlActionExecutor.h"
+#include "xml/XmlDom.h"
+#include "xml/XmlUtil.h"
+
+namespace aapt {
+
+namespace {
+
+using ::aapt::configuration::Abi;
+using ::aapt::configuration::AndroidManifest;
+using ::aapt::configuration::AndroidSdk;
+using ::aapt::configuration::Artifact;
+using ::aapt::configuration::Configuration;
+using ::aapt::configuration::GlTexture;
+using ::aapt::configuration::Group;
+using ::aapt::configuration::Locale;
+using ::aapt::util::TrimWhitespace;
+using ::aapt::xml::Element;
+using ::aapt::xml::FindRootElement;
+using ::aapt::xml::NodeCast;
+using ::aapt::xml::XmlActionExecutor;
+using ::aapt::xml::XmlActionExecutorPolicy;
+using ::aapt::xml::XmlNodeAction;
+
+const std::unordered_map<std::string, Abi> kAbiMap = {
+    {"armeabi", Abi::kArmeV6},
+    {"armeabi-v7a", Abi::kArmV7a},
+    {"arm64-v8a", Abi::kArm64V8a},
+    {"x86", Abi::kX86},
+    {"x86_64", Abi::kX86_64},
+    {"mips", Abi::kMips},
+    {"mips64", Abi::kMips64},
+    {"universal", Abi::kUniversal},
+};
+
+constexpr const char* kAaptXmlNs = "http://schemas.android.com/tools/aapt";
+
+/** A default noop diagnostics context. */
+class NoopDiagnostics : public IDiagnostics {
+ public:
+  void Log(Level level, DiagMessageActual& actualMsg) override {}
+};
+NoopDiagnostics noop_;
+
+std::string GetLabel(const Element* element, IDiagnostics* diag) {
+  std::string label;
+  for (const auto& attr : element->attributes) {
+    if (attr.name == "label") {
+      label = attr.value;
+      break;
+    }
+  }
+
+  if (label.empty()) {
+    diag->Error(DiagMessage() << "No label found for element " << element->name);
+  }
+  return label;
+}
+
+/** XML node visitor that removes all of the namespace URIs from the node and all children. */
+class NamespaceVisitor : public xml::Visitor {
+ public:
+  void Visit(xml::Element* node) override {
+    node->namespace_uri.clear();
+    VisitChildren(node);
+  }
+};
+
+}  // namespace
+
+ConfigurationParser::ConfigurationParser(std::string contents)
+    : contents_(std::move(contents)),
+      diag_(&noop_) {
+}
+
+Maybe<Configuration> ConfigurationParser::Parse() {
+  std::istringstream in(contents_);
+
+  auto doc = xml::Inflate(&in, diag_, Source("config.xml"));
+  if (!doc) {
+    return {};
+  }
+
+  // Strip any namespaces from the XML as the XmlActionExecutor ignores anything with a namespace.
+  auto* root = FindRootElement(doc.get());
+  if (root == nullptr) {
+    diag_->Error(DiagMessage() << "Could not find the root element in the XML document");
+    return {};
+  }
+
+  std::string& xml_ns = root->namespace_uri;
+  if (!xml_ns.empty()) {
+    if (xml_ns != kAaptXmlNs) {
+      diag_->Error(DiagMessage() << "Unknown namespace found on root element: " << xml_ns);
+      return {};
+    }
+
+    xml_ns.clear();
+    NamespaceVisitor visitor;
+    root->Accept(&visitor);
+  }
+
+  XmlActionExecutor executor;
+  XmlNodeAction& root_action = executor["post-process"];
+  XmlNodeAction& artifacts_action = root_action["artifacts"];
+  XmlNodeAction& groups_action = root_action["groups"];
+
+  Configuration config;
+
+  // Helper to bind a static method to an action handler in the DOM executor.
+  auto bind_handler = [&config](std::function<bool(Configuration*, Element*, IDiagnostics*)> h)
+      -> XmlNodeAction::ActionFuncWithDiag {
+    return std::bind(h, &config, std::placeholders::_1, std::placeholders::_2);
+  };
+
+  // Parse the artifact elements.
+  artifacts_action["artifact"].Action(bind_handler(artifact_handler_));
+  artifacts_action["artifact-format"].Action(bind_handler(artifact_format_handler_));
+
+  // Parse the different configuration groups.
+  groups_action["abi-group"].Action(bind_handler(abi_group_handler_));
+  groups_action["screen-density-group"].Action(bind_handler(screen_density_group_handler_));
+  groups_action["locale-group"].Action(bind_handler(locale_group_handler_));
+  groups_action["android-sdk-group"].Action(bind_handler(android_sdk_group_handler_));
+  groups_action["gl-texture-group"].Action(bind_handler(gl_texture_group_handler_));
+  groups_action["device-feature-group"].Action(bind_handler(device_feature_group_handler_));
+
+  if (!executor.Execute(XmlActionExecutorPolicy::kNone, diag_, doc.get())) {
+    diag_->Error(DiagMessage() << "Could not process XML document");
+    return {};
+  }
+
+  return {config};
+}
+
+ConfigurationParser::ActionHandler ConfigurationParser::artifact_handler_ =
+    [](Configuration* config, Element* root_element, IDiagnostics* diag) -> bool {
+      Artifact artifact{};
+      for (const auto& attr : root_element->attributes) {
+        if (attr.name == "name") {
+          artifact.name = attr.value;
+        } else if (attr.name == "abi-group") {
+          artifact.abi_group = {attr.value};
+        } else if (attr.name == "screen-density-group") {
+          artifact.screen_density_group = {attr.value};
+        } else if (attr.name == "locale-group") {
+          artifact.locale_group = {attr.value};
+        } else if (attr.name == "android-sdk-group") {
+          artifact.android_sdk_group = {attr.value};
+        } else if (attr.name == "gl-texture-group") {
+          artifact.gl_texture_group = {attr.value};
+        } else if (attr.name == "device-feature-group") {
+          artifact.device_feature_group = {attr.value};
+        } else {
+          diag->Note(
+              DiagMessage() << "Unknown artifact attribute: " << attr.name << " = " << attr.value);
+        }
+      }
+      config->artifacts[artifact.name] = artifact;
+      return true;
+    };
+
+ConfigurationParser::ActionHandler ConfigurationParser::artifact_format_handler_ =
+    [](Configuration* config, Element* root_element, IDiagnostics* diag) -> bool {
+      for (auto& node : root_element->children) {
+        xml::Text* t;
+        if ((t = NodeCast<xml::Text>(node.get())) != nullptr) {
+          config->artifact_format = TrimWhitespace(t->text).to_string();
+          break;
+        }
+      }
+      return true;
+    };
+
+ConfigurationParser::ActionHandler ConfigurationParser::abi_group_handler_ =
+    [](Configuration* config, Element* root_element, IDiagnostics* diag) -> bool {
+      std::string label = GetLabel(root_element, diag);
+      if (label.empty()) {
+        return false;
+      }
+
+      auto& group = config->abi_groups[label];
+      bool valid = true;
+
+      for (auto* child : root_element->GetChildElements()) {
+        if (child->name != "abi") {
+          diag->Error(
+              DiagMessage() << "Unexpected element in ABI group: " << child->name);
+          valid = false;
+        } else {
+          for (auto& node : child->children) {
+            xml::Text* t;
+            if ((t = NodeCast<xml::Text>(node.get())) != nullptr) {
+              group.push_back(kAbiMap.at(TrimWhitespace(t->text).to_string()));
+              break;
+            }
+          }
+        }
+      }
+
+      return valid;
+    };
+
+ConfigurationParser::ActionHandler ConfigurationParser::screen_density_group_handler_ =
+    [](Configuration* config, Element* root_element, IDiagnostics* diag) -> bool {
+      std::string label = GetLabel(root_element, diag);
+      if (label.empty()) {
+        return false;
+      }
+
+      auto& group = config->screen_density_groups[label];
+      bool valid = true;
+
+      for (auto* child : root_element->GetChildElements()) {
+        if (child->name != "screen-density") {
+          diag->Error(
+              DiagMessage() << "Unexpected root_element in screen density group: "
+                            << child->name);
+          valid = false;
+        } else {
+          for (auto& node : child->children) {
+            xml::Text* t;
+            if ((t = NodeCast<xml::Text>(node.get())) != nullptr) {
+              ConfigDescription config_descriptor;
+              const android::StringPiece& text = TrimWhitespace(t->text);
+              if (ConfigDescription::Parse(text, &config_descriptor)) {
+                // Copy the density with the minimum SDK version stripped out.
+                group.push_back(config_descriptor.CopyWithoutSdkVersion());
+              } else {
+                diag->Error(
+                    DiagMessage() << "Could not parse config descriptor for screen-density: "
+                                  << text);
+                valid = false;
+              }
+              break;
+            }
+          }
+        }
+      }
+
+      return valid;
+    };
+
+ConfigurationParser::ActionHandler ConfigurationParser::locale_group_handler_ =
+    [](Configuration* config, Element* root_element, IDiagnostics* diag) -> bool {
+      std::string label = GetLabel(root_element, diag);
+      if (label.empty()) {
+        return false;
+      }
+
+      auto& group = config->locale_groups[label];
+      bool valid = true;
+
+      for (auto* child : root_element->GetChildElements()) {
+        if (child->name != "locale") {
+          diag->Error(
+              DiagMessage() << "Unexpected root_element in screen density group: "
+                            << child->name);
+          valid = false;
+        } else {
+          Locale entry;
+          for (const auto& attr : child->attributes) {
+            if (attr.name == "lang") {
+              entry.lang = {attr.value};
+            } else if (attr.name == "region") {
+              entry.region = {attr.value};
+            } else {
+              diag->Warn(DiagMessage() << "Unknown attribute: " << attr.name
+                                       << " = " << attr.value);
+            }
+          }
+          group.push_back(entry);
+        }
+      }
+
+      return valid;
+    };
+
+ConfigurationParser::ActionHandler ConfigurationParser::android_sdk_group_handler_ =
+    [](Configuration* config, Element* root_element, IDiagnostics* diag) -> bool {
+      std::string label = GetLabel(root_element, diag);
+      if (label.empty()) {
+        return false;
+      }
+
+      auto& group = config->android_sdk_groups[label];
+      bool valid = true;
+
+      for (auto* child : root_element->GetChildElements()) {
+        if (child->name != "android-sdk") {
+          diag->Error(
+              DiagMessage() << "Unexpected root_element in ABI group: " << child->name);
+          valid = false;
+        } else {
+          AndroidSdk entry;
+          for (const auto& attr : child->attributes) {
+            if (attr.name == "minSdkVersion") {
+              entry.min_sdk_version = {attr.value};
+            } else if (attr.name == "targetSdkVersion") {
+              entry.target_sdk_version = {attr.value};
+            } else if (attr.name == "maxSdkVersion") {
+              entry.max_sdk_version = {attr.value};
+            } else {
+              diag->Warn(DiagMessage() << "Unknown attribute: " << attr.name
+                                       << " = " << attr.value);
+            }
+          }
+
+          // TODO: Fill in the manifest details when they are finalised.
+          for (auto node : child->GetChildElements()) {
+            if (node->name == "manifest") {
+              if (entry.manifest) {
+                diag->Warn(DiagMessage() << "Found multiple manifest tags. Ignoring duplicates.");
+                continue;
+              }
+              entry.manifest = {AndroidManifest()};
+            }
+          }
+
+          group.push_back(entry);
+        }
+      }
+
+      return valid;
+    };
+
+ConfigurationParser::ActionHandler ConfigurationParser::gl_texture_group_handler_ =
+    [](Configuration* config, Element* root_element, IDiagnostics* diag) -> bool {
+      std::string label = GetLabel(root_element, diag);
+      if (label.empty()) {
+        return false;
+      }
+
+      auto& group = config->gl_texture_groups[label];
+      bool valid = true;
+
+      GlTexture result;
+      for (auto* child : root_element->GetChildElements()) {
+        if (child->name != "gl-texture") {
+          diag->Error(
+              DiagMessage() << "Unexpected element in GL texture group: "
+                            << child->name);
+          valid = false;
+        } else {
+          for (const auto& attr : child->attributes) {
+            if (attr.name == "name") {
+              result.name = attr.value;
+              break;
+            }
+          }
+
+          for (auto* element : child->GetChildElements()) {
+            if (element->name != "texture-path") {
+              diag->Error(
+                  DiagMessage() << "Unexpected element in gl-texture element: "
+                                << child->name);
+              valid = false;
+              continue;
+            }
+            for (auto& node : element->children) {
+              xml::Text* t;
+              if ((t = NodeCast<xml::Text>(node.get())) != nullptr) {
+                result.texture_paths.push_back(TrimWhitespace(t->text).to_string());
+              }
+            }
+          }
+        }
+        group.push_back(result);
+      }
+
+      return valid;
+    };
+
+ConfigurationParser::ActionHandler ConfigurationParser::device_feature_group_handler_ =
+    [](Configuration* config, Element* root_element, IDiagnostics* diag) -> bool {
+      std::string label = GetLabel(root_element, diag);
+      if (label.empty()) {
+        return false;
+      }
+
+      auto& group = config->device_feature_groups[label];
+      bool valid = true;
+
+      for (auto* child : root_element->GetChildElements()) {
+        if (child->name != "supports-feature") {
+          diag->Error(
+              DiagMessage() << "Unexpected root_element in device feature group: "
+                            << child->name);
+          valid = false;
+        } else {
+          for (auto& node : child->children) {
+            xml::Text* t;
+            if ((t = NodeCast<xml::Text>(node.get())) != nullptr) {
+              group.push_back(TrimWhitespace(t->text).to_string());
+              break;
+            }
+          }
+        }
+      }
+
+      return valid;
+    };
+
+}  // namespace aapt